<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>collections</title>
    <script type="text/javascript" src="https://d3js.org/d3.v4.min.js"></script>
</head>

<body>
</body>
<script>
    var month = { "jan": 1, "Feb": 2, "mar": 3, "apr": 4 };
    console.log(d3.keys(month));
    console.log(d3.values(month));
    console.log(d3.entries(month));
</script>

</html>